Vise Grip Kinetic Analysis:
This is my personal Summer 2021 Project
I modeled a mechanism that embodies incredible engineering design: the Vise Grip. This mechanism makes beautiful use of a 4-bar linkage to achieve mechanical advantage. I grabbed a vise grip from my toolbox, took some critical measurements, and reflected the design of the linkage. The video to the right shows the vise grip moving through its range of motion.
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I also performed a dynamic analysis by hand using two techniques to prove that I have successfully captured the dynamics of the mechanism. The mechanical advantage is solved in the images below for the orientation of the vise grip shown (very similar results between methods).
4 Bar Linkage Decomposition
Method I: FBD Force Analysis
Mechanical Advantage (M.A. ≈ 2.57)
Method II: Instant Centers Analysis
Mechanical Advantage (M.A. ≈ 2.62)
What I Learned
I learned how to show confidence in analytical work. My favorite method: derive at least two models using different formulations and show they converge on the same result. A classic example is applying Newtonian and Lagrangian mechanics to the same system — if both arrive at the same answer, you've got something real.